Inhibition of Mycelial Growth of Rhizoctonia Solani by Chitosan in vitro and in vivo

Abstract

Objective: Evaluate the antifungal effect of chitosan against Rhizoctonia solani in vitro and the possible mechanisms of its induced activity in potato tubers to control black scurf disease. Methods: The in vitro influence of chitosan at different concentrations on mycelial growth of R. solani was tested by using the poisoned food technique in PDA medium. The effect of these concentrations on the development of lesion diameters in tubers inoculated with R. solani mycelium was assayed for 30 days. The concentration that showed the greatest inhibitory effect on lesion diameters was tested to assess the induced activity of defense-related enzymes in the infected tubers. Results: In the poisoned food technique, chitosan at 1% completely inhibited the growth of R. solani mycelium. In vivo tests showed that chitosan treatment at 0.5% effectively controlled the black scurf in tubers inoculated with R. solani mycelium. Chitosan increased the activities of defense-related enzymes such as Peroxidase (POD), Polyphenol Oxidase (PPO) and Phenylalanine Ammonia-lyase (PAL) in treated tubers of tested cultivars. Conclusion: This work demonstrated that chitosan directly inhibited the growth of R. solani, and potentially elicited defense reaction in potato tubers.

Antifungal Activity of Squid Pen Chitosan Nanoparticles against Three Fungal Pathogens in Various Citrus Fruits In Vitro and In Vivo

“…In addition, the higher the concentration used, the higher the antifungal activity observed in our tests. The concentration-dependent phenomenon was also reported in previous research [17,33,34], which may be due to the strong interactions between chitosan's positive charges and the cell's negatively charged membranes [35]. As can be seen from the figures, SCNs wholly suppressed the mycelium linear growth, and biomass tested at a concentration of 200 ppm.…”

“…Chitosan has been reported to have high fungal activity against many phytopathogenic fungi [10,11], which cause several fungal plant diseases [12][13][14]. Recently, chitosan-based nanoparticles have been widely studied for various applications because of their small size, good biocompatibility and degradability, high permeability, high antimicrobial property, low cost, and facile preparation [15][16][17][18][19]. Practically, chitosan nanoparticles have affected and prevented the growth of fungi on citrus fruits, such as P. steckii and A. oryzae [17], C. albicans [20,21], A. fumigatus [22], and Xanthomonas oryzae pv.…”

Combined Influence of Chitosan and Calcium Chloride on Fusarium Dry Rot Disease Under Field Conditions

“…Chitosan at 4.0 g/l applied as soil drench showed significant levels of protection against soil-borne fungi, for example, Fusarium wilt on potato plants [38] and tomato [39]. Chitosan can induce defense activity in potato tubers against Fusarium dry rot [40] and Rhizoctonia solani [12]. Pre-harvest application with CaCl 2 and Chitosan was effective in minimizing weight loss and decay, as well as in maintaining maximum firmness and lengthening the shelf life of "Early Swelling" peach [41].…”

“…Chitosan (β-1,4-D-glucosamine), is a natural biopolymer obtained by deacetylation of chitin, the second most plentiful natural polymer in the world [10]. Chitosan is a resistance activator and an antifungal agent [11,12]. Many studies showed that chitosan could increase productivity, reduce transpiration, and induce more resistance to fungal, bacterial, and viral infections [13,14].…”

“…Chitosan with high and low molecular weight and a hydrolyzed chitosan derivative applied on 31, 45, and 59 days after planting increase the size of tubers in two different potato varieties [19]. Mohammed et al (2019) [12] stated that chitosan could inhibit the mycelial growth of Rhizoctonia solani AG-3 and induce a defense reaction in potato tubers. Calcium (Ca) is an essential secondary nutrient and a vital factor in plant growth.…”